Electric switch



Jan. 17, 1928. 1,656,703

B. E. GETCHELL ELECTRIC SWITCH Filed Sept. 4 1926 4 Sheets-Sheet 1 fi -L Jan. 17, 1928. 1,656,703

B. E. GETCHELL ELECTRIC SWITCH Filed Sept. 4. 1926 4 Sheets-Sheet 2 INVENTOR Bely'amz'n L Gate]: e1],

Jan. 17, 1928.

B. E. GETCHELL ELECTRIC SWITCH Filed Sept. 4 1926 4 Sheets-Sheet 3 INVENTOR amz'n l 1 etc/2e11,

Ben

.Fan. 17, 1928.

B. E. GETCHELL ELECTRIC SWITCH Filed Sept. 4 1926 4 Sheets-Sheet 4 INVENTOR E. Q tehell,

Benjamin Patented Jan. 17, 1928.

UNITED STATES A 1,656,703 PATENT OFFICE.

BENJAMIN E. GETCHELL, OF PLAINVILLE, CONNECTICUT, ASSIGNOR TO THE TRUM- BULL ELECTRIC MANUFACTURING CO CORPORATION OF CONNECTICUT.

ELECTBI MPANY, OF PLAINVILLE, CONNECTICUT, A

c SWITCH.

Application filed September 4, 1926. Serial No. 183,722.

The main object of this invention is to rovide a practical and dependable means or preventing the formation of'an injurious arc in the opening movement of the switch and for effectually snufing out such minor arcing as may form.

Another object ,is to provide a snufling means which will confine the arc laterally with respect to the blades and contacts and thus prevent the jum ing of the arc to adjacent blades or switc parts.

Another object is to provide an arc snuffing means articularly adapted for use .in a double tiirow switch construction, and which will also act to hold or retain the blades of a double throw switch in neutral position when the switch is ofi.

- Another object is to provide an arc snuifing means with its parts so designed and proportioned that it will also automatically operateto latch the switch in the on position, and assist in the openingmovement of the switch after the switch has been manually moved from the latched on position, and act as a suitable stop in the opening movement of the switch. I K The invention is shown as applied in commercial practice to a threeole, double-throw enclosed switch of the kni e blade type, but, obviously the invention may be used, in whole or in part, in different types of switches having one or more blades or different types of contacts.

The quick-break arrangement shown in the drawings is fully described in my former Patent No. 1,483,846. This patent also shows the method of mounting a switch of this description in a box and providing it with an external operating han 1e. My former Patents Nos. 1,407,852 and 1,473,574: disclose arc snufling arrangements iavin some generally similar characteristics, but t .ese constructions as shown are adapted only to single-throw switches and-cannot be used in a double-throw construction.

The present invention consists of providing an insulating housing or are snufiing rocker and pivoting the rocker to or adjacent the contact jaw of the switch and further providing the blade of the switch with an insulating block, the rocker being provided with spring means tending .tomove the rocker over the top of the contact-jaw and between the j aw and the blade and the block 011 the blade co-operating withthe rocker to block the path of the are as the switch blades are being opened. The blade is provided with rollers which bear upon the side plates of the rocker with a cam movement which moves the rocker out of the path of the blade in the switch closing movement.

The rollers also co-operate with suitable shoulders on the side plates of the rocker to latch the switch in closed position.

The ro'llers also co-operate with another part of the side plates of one of the rockers to form a stop for the switch when it is being moved to neutral position.

The rollers further cc-operate with the s1de plates of a pair of oppositely disposed roclrers to hold or retain the switch in neutral position.

The spring the rollers assists 111 the opening movement of the switch after the latching engagement of the rocker and rollers has been broken.

Fig. 1 is a front view of one form of construction showing a switch with three units, the circuit being closed with one set of contacts.

Fig. 2 is a side view of the same, showing the supporting base in section.

Fig. 3 is a fragmentary sectional view on a larger scale showing the switch in the neutral or open circuit position.

Fig. 4. is a similar section and side view showing the switch closed at one side and about to be opened. This also shows in dot and dash lines parts of the switch in intermediate position.

- Fig. 5 is a fragmentary end view showing the method of supporting one or the shield members.

Fig. 6 is a detail end view of one of the blades and parts carried by it.

Fig. 7 is an exploded perspective view showlng one of the switch blades, one of the switch contacts, and a shield.

Fig. 8 is a front view on a reduced scale showing one form of casing with the interior parts added.

Fig. 9 is a side view of the same.

The switch jaws or contacts 10 and 11 may be'of any suitable type and are disposed opposite each other as is customary in double throw switches. I have also shown fuses 12 and 13 which are ordinarily employed in switches of this type, but which are pressure of the side plates upon not material to this invention. Circuit terminals 14 and 15 are also provided as usual. The entire construction is mounted on an insulating base 16 of any suitable character.

The movable-switch member 17 is preferably hinged at 18 to a standard secured to the base in the usual manner. Each switch member has two blades 19 and 20, the outer ends of which are adapted to co-act, respectively, with the stationary contacts 10 and 11. The switch may have any number of switch units such as 17, and they are preferably connected by a cross-bar 21 of insulating material. An operating crank 22 of any suitable type is supported in any-suitable manner, as for instance, in the opposite sides of the box 23, and provided with an external handle or lever 24. The box is provided with a cover 25 of an suitable type.

The switch is preferably 0t what is known as the quick-break types A bracket 26 is securedto the cross-bar 21 and supports the hinged arms 27 and 28 which are normally drawn toward each other by the spring 29. Theybracket is provided with projections30 and 30 which serve as stops for the arms 27 and 28, respectively. When the crank 22 is moved in thedirection of the arrow of Fig. 4, it'tilts the arm 28 so that it engages the shoulder 30 and places the spring 29 under tension. Continued movement of the crank 22 flexibly moves the switch member 17 until the blade 19 is free from the contact jaw 10, whereupon the spring 29, through its connection with the arm 27 suddenly throws the switch member 17 so as to separate the blade 19 from the contact 10 with a snap action or a quick-break, as it is sometimes called.

A shield member is formed of insulating material and preferably consists oftwo side plates 31 and 32 with an intervening barrier 33. The shield is hinged or pivoted on the pin 34 which extends through the contact member 11. It will be understood, of course, that. the shield member 32' at the right of Fig. 4 is constructed in the same manner as the one illustrated at the left in Fig. 7. Springs 35 and 36 on the ends of the pin 34 engage the plates 31 and 32 so as to press the shield toward the center of the switch. The pin 37 serves as an abutment for the lugs 38 when the parts are in the position shown at the left in Figs. 3 and 4:.

The switch blade 20 is provided "with projections 39 on opposite sides which are referably in the form of rotatable rollers a apted to roll alon the curved edges 40 of the shield. Each lade such as 20 is provided wititan insulating block 41 on its lower edge leavinithe outer end of the blade free to engage t e stationary contact 11. The shield plates 31 and 32 are hinged on opposite sides of the contact 11, and a groove'42 is left between them so as to allow for the movement of the ends of the switch blades 20 and the member 17 in the central position. When it is desired to close the switch, the member 17 is tilted to the right, as viewed in Figs. 3 and 4, whereupon the projecting rollers 39' roll or slide along the curved edge 40' of the shield'32 and force the shield out of the way of the blade 19 which is then allowed to engage the contact 10. When the blade 19 is entirely or fully closed against contact jaws 10, the shoulder 43 on the shield 32 presses down against the projection 39' and thus holds the switch member in the closed circuit position.

' When it is desired to open the circuit, the crank 22 is moved in the direction of the arrow of Fig. 4 as above mentioned. The projection 39 sliding alon the shoulder 43 tiltsthe shield 32 out 0% the way of the blade 19 and the blade is allowed to leave the contact 10. As the tip of the blade leaves the contact, the shield carrier 33 moves across the outer end, of the contact 10 to cut ofi any arc which might tend to follow. The insulating block 41' on the lower edge of the blade 19 prevents the are from traveling along the lower edge of the blade. The channel-like construction of the shield confines any are which is formed between the walls of the shield and the stop 41 so that the are cannot travel laterally to any other conducting part or any adjacent wall of the'box. It will also be noted that the shoulder -being spring-pressed, tends to assist in the opening movement by its pressure against the projections 39. Obviously, the

operation of closing the circuit through the blade 20 in contact with jaws 11 would be effected in the same manner as closing the blade 19 against the jaw 10 and the opening of the circuit through blade 20 and contact 11 would alsocorrespond to the action above described.

I claim:

1. In a switch, a stationary contact, an

retract said shield and adapted to be assisted toward the open position by said shield.

4. A switch including a contact, a grooved insulating shield hinged in co-operating relation therewith, a hinged blade for said contact, and an insulating block on the edge of the blade adapted to move into the groove of said shield.

5. In a double throw switch, hinged blades, stationary contacts therefor,aspring pressedinsulating shield co-acting with each contact and mounted to move with and as sist in the opening movement of the switch after the initial manual opening movement of said blades.

6. In a double throw switch, a pair of contacts, a hinged member having a blade for each of said contacts and spring pressed'insulating shields co-act-ing between each blade and its contact and having means for pressing against said blades to yieldingly hold them closed.

7 A switch construction including a etationary contact, a movable blade for engagement with said contact, an insulating shield having operable connection with said contact, spring means to force said shield between said contact and said blade in the K opening movement of said blade and roller means carried by said blade for moving said shield away from the path of said blade in the closing movement of said blade.

8. A switch construction including a stationary contact, a movable blade associated with said contact, an insulating shield associated with said contact and adapted to move between said contact and said blade in the opening movement of said blade, a spring tendlng to move said shield into said interposed position, means carried by said blade to move said shield away from the path of said blade in the closing movement of said blade, a groove in said shield and an insulating member carried by said bladeto cooperate with said groove. 7

9. A switch construction including a stationary contact, a movable blade associated with said contact, an insulating shield assogrooved s ciated with said contact and ada ted to move between said contact and said lade in the opening movement of said blade, a spring tending to move. said snield into said interposed position, means carried by said blade to move said shield away from the path of said blade in the closing movement of said blade, a groove in said shield and an insulating member'carried by said blade to cooperate with said groove to block the ath of the arc in the opening movement 0t the blade.

10. A switch construction including a stationary contact,. a movable switch blade for engagement with said contact, a movable insulating shield having a roove, spring means for moving said shield between said contact and said blade in the opening move-. ment of said blade, means carried by the blade for moving said shield away from the path of said blade in the closing movement of said blade, an insulating member carried by said blade to cooperate with said shield and said groove to block the path of the electric arc in the opening movement of said blade.

11. In an electric switch the combination of a stationary contact, a hinged blade having a movable end adapted to engage said contact, an insulating shield hinged adjacent said contact on an axis substantially parallel to the axis of said blade, a sprin tending to press said shield toward sai blade, said blade having a projection adapted to engage an edge of said shield in the circuit closing movement of said blade and said shield having a shoulder for engagm said blade to yieldingly hold it in its closed circuit position.

12. An electric switch comprising a hinged blade having a movable end, a contact ada ted to be engaged thereby, a ield hinged ad acent said contact and an insulating member carried by one edge of said blade between its ends and adapted to move in the cove of said shield.

BENJAMIN E. GETCHELL. 

